Electric lamp and mounting therefor



Dec. 8, 1936. w. J. GEIGER ET AL 2,063,090

ELECTRIC LAMP AND MOUNTING THEREFOR Filed April 6, 1955 [ATE/ENTER 5 WI,TEE. JG IEER 3-7 AL FREE 7? GASKYLL THEIF; ATTQRNEY Patented Dec. 8,1936 UNITED STATES ELECTRIC LAMP AND MOUNTING THEREFOR Walter J. Geiger,Cleveland Heights, and Alfred T. Gaskill, Cleveland, Ohio, assignors toGeneral Electric Company, a corporation of New York Application April 6,1933, Serial No. 664,748

4 Claims.

Our invention relates to mountings for electric lamps and the like, andis especially adaptable and useful in cases where the light sourceshould occupy a definite position with reference to some associated partor structure, such as a reflector or a lens. The invention is ofparticular advantage for projection lamps such as vehicle headlamps, inwhich an incandescent filament lamp is mounted in a reflector such asthe well-known paraboloid reflector.

In headlamps as at present constructed, the lamp is mounted by insertingits bayonet base in a tubular bayonet socket which is itself mounted inan opening at the apex of the reflector, with suitable provisions foradjusting the socket relative to the reflector to focus the light sourceof the lamp to exactly the right position for any desired'distributionof light. While this arrangement permits easy removal and replacement ofa lamp as Well as accurate focusing, yet it is mechanically complicated,and often liable to derangements which allow the lamp to shift out offocus.

To overcome these disadvantages of present practice, we prefer to mountthe lamp base more directly on the reflector, without the interventionof a socket and adjusting means therefor. This We do in such a way thatwhen a given lamp is once properly focused in a reflector, thisadjustment becomes permanently fixed; although the particular lamp canstill be removed and replaced as often as desired,-for cleaning of thelamp or its reflector, etc. In this way, we are able to dispense withthe usual lamp socket, as well as with its focusing mechanism.

For removably mounting the lamp, we provide its base with engagementmeans adapted to engage in perfectly definite relation with anaccurately located and fixed part or engagement means of the reflector,provision being also made for holding these parts in proper engagement.This requires of course that the engagement means on the base beproperly adjusted and fixed relative to the light source; and while thismay be accomplished by extreme accuracy in the basing of the lamp, yetwe prefer to embody the engagement means of the base in a separate partor adapter that can be properly adjusted on the base in focusing andpermanently fixed thereto,--as by soldering, or other methods of forminga fused joint. The lamp I-or, more properly speaking, its base with theproperly focused adapter thereon-is inserted in an opening in the apexof the reflector, and the adapter is held properly engaged with thereflector by novel spring actuated means associated with the latter.Further features and advantages of our invention will appear from thefollowing description of species thereof and from the drawing.

end of said base.

In the drawing, Fig. 1 is a partially sectioned elevation of a headlampemploying a form of mounting comprising our invention; Fig. 2 is adisassembled perspective'view of the mounting and lamp; Fig. 3 is a sideview in section of electrical connection means for the lamp; Fig. 4 is aside view of a modified form of adapter; and Fig. 5 is a plan Viewthereof. 4

Referring to Figs. 1 and 2, the lamp, indicated generally by the numeralID, comprises a bulb II having a filament I2 sealed therein and mountedon leading-in wires I3. A base l4 comprising a tubular shell I4 ismounted on said bulb I I, and carries a terminal pin I5 mounted ininsulating material I6 and protruding rearward beyond the One of theleading-in wires I3 is connected to the base shell I4 and the other isconnected to the pin I5. On the base I4 is mounted an adapter II. Thisadapter II has an enlarged tubular portion I8 which fits in a hole I9 ina flattened portion 20 at the apex of the reflector H. The enlargedportion I8 tapers down rearward to a comparatively narrow tubularportion 22, which surrounds the base I4. A flange 23 is formed at theforward end of the portion I8, adjacent the lamp Ill, for determiningthe longitudinal and axial position of the lamp in the reflectoropening. The adapter II has engagement means for locking the lamp I0against turning in the reflector opening (as hereinafter described),such as a rearwardly projecting lug 24 on the rim of said flange. Theadapter II is located on the base 54 so that the rear surface of theflange 23 bears a definite relation to the filament I2, the reducedadapter portion 22 being of slightly larger diameter than the base, sothat the lamp may be rocked in the adapter to locate the filament bothaxially and longitudinally, and may also be turned to locate itangularly with reference to the lug 2d. When the filament I2 has beenthus prefocused, the adapter I! is fixed to the'shell I4, preferably bysolder 25.

The lamp Ill is placed in the reflector 2i so that the rear surface orshoulder of the flange 23 bears against the inside surface of theflattened portion 20, which is definitely located with respect to thefocal point of the reflector, and the lug 24 enters a seat formed by arecess or opening 26 in said reflector-thus definitely locating thefilament to give the desired distribution of light. The flange 23 isheld against the reflector by spring-actuated retaining means,hereinafter described, which engage an annular retaining lip 21 on therear end portion 22 of the adapter II. The retaining lip 27! is beveledat its rear surface, and presents a square shoulder forward, toward thebulb. It is no larger, at least, than the portion l8, which may fit theopening l9 easily but without play.

' The spring-actuated retaining means for engaging the adapter shoulderat 21 are distributed around the lamp base opening IQ of the reflector2|, and in the present instance have the character of independent springcatches embodiedin a spring holder 28 mounted on the rear of thereflector portion 20. The spring holder 28 comprises a flat annularportion 29 with a hole 30 therein of substantially the same diameter asthe hole IS in the reflector 2|. This holder 28 is held on the reflectorby a pair of oppositely located lugs or tongues 3| which engage in holes32 in said reflector. A plurality of retroverted or bowed spring fingers33 (three being shown) extend outward, rearward, and inward again fromthe periphery of the portion 29, and have rearward bent latch tips 34 attheir ends. These tips 34 of the spring catches 33 coact with the rearbevel on the annular lip 21 of the adapter H, as well as with its frontshoulder; i.. e., when the catches 33 snap over the lip 21 and engagebe-- hind its shoulder they are held there, besides holding the lampbase |4 pressed home in the reflector opening IS, with the flange 23firmly against the flattened portion 20 of the reflector all around theopening IS. A slot 35 is provided in the rim of the holder portion 29corresponding to the opening 26 in the reflector, to accommodate the lug24. The lug 24 not only looks the lamp In in proper angular relation tothe reflector 2|, but also makes it virtually impossible to secure thelamp in any wrong angular relation, because of the impossibility ofengaging the spring catches 33 2hinder the lip 21 unless the lug 24 isseated at Obviously the insertion-limiting shoulder or flange of theadapter need not be continuous as in Fi 2; on the contrary, it may beinterrupted even to the extent shown in Figs. 4 and 5, where threeproperly distributed arms 'or lugs 36-3|38 are substituted for theflange 23, an anti-turning key lug 39 similar to lug 24 being providedon lug 36. It may be preferable to employ such lugs in view of the factthat a solid flange is liable to warp. v

Electrical connection may be made to the lamp III by a helical springconnector 40 (Fig. 3) which is slipped over the pin l5 of the lamp. Saidconnector 40 comprises a helical spring 4|, one end of which is clampedon a metal sleeve 42 mounted on the end of the insulating covering 43 ofa stranded conductor 44 which is in contact with said sleeve. The spring4| is deformed so that the axis thereof is not a straight line. In thepreferred form a number of turns 45 at the opposite end of said spring4| are offset axially with respect to the remaining turns, thus insuringa firm contact of said spring with the pin I5 which brings the axis ofthe spring back to a straight line. An insulating covering 46,preferably a soft rubber tube, surrounds the said spring 4|.

What we claim as new and desire to secure by Letters Patent of theUnited States is:

1. The combination of a reflector having a lamp base opening therein,with a lamp comprising a bulb and a base having a portion ofsubstantially the same diameter as said opening with a lateralprojection thereon forming an external shoulder seating directly in saidreflector opening, said lateral projection engaging one side of themargin around the said opening in said reflector, another externalshoulder on said base on the opposite side of said reflector, and aspring disposed between said reflector and said second mentionedshoulder and exerting a pressure axially oi the lamp to hold saidlateral projection against said reflector margin.

2. The combination of a reflector having a lamp base opening therein,with a lamp comprising a bulb and a base having a portion ofsubstantially the same diameter as said opening with a lateralprojection thereon adjacent said bulb forming an external shoulderseating directly in said reflector opening, said lateral projectionengaging the inside of the margin around the said openingin saidreflector, another external shoulder on said base behind said reflector,and a spring disposed between the back of said reflector and said secondmentioned shoulder and exerting a pressure rearwardly of the lamp tohold said lateral projection against said reflector margin.

3. The combination of a reflector having a lamp base opening therein,with a lamp comprising a bulb and a base having an enlarged portion ofsubstantially the same diameter as saidopening with a lateral projectionthereon adjacent said bulb forming an external shoulder seating directlyin said reflector opening, said lateral projection engaging the insideof the margin around the said opening in said reflector, anotherexternal shoulder on said base behind said reflector not exceeding thesaid enlarged portion in size, and a spring disposed between the back ofsaid reflector and said second mentioned shoulder and exerting apressure rearwardly of the lamp to hold said lateral projection againstsaid reflector.

4. An electric lamp comprising a bulb and a base and an adapter fixed onsaid base in focus adjustment, said adapter consisting of a metal shellcomprising an enlarged cylindrical portion at one end with a lateral'projection on one end thereof forming an external seating shoulder, areduced cylindrical portion adjacent the opposite end of said enlargedportion surrounding said base'and secured thereto, and an outwardlybeveled lip at the end of the said reduced portion of said adapterconstituting a shoulder facing said first mentioned shoulder and notexceeding said enlarged portion of said adapter in size.

WALTER J. GEIGER. ALFRED 'r. GASKILL.

